SUNLAND, CA - DECEMBER 05: A house burns during the Creek Fire on December 5, 2017 in Sunland, California. Strong Santa Ana winds are rapidly pushing multiple wildfires across the region, expanding across tens of thousands of acres and destroying hundreds of homes and structures. (Photo by David McNew/Getty Images)

David McNew

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A new wildfire closed part of Interstate 405 early Wednesday near Los Angeles' posh Bel Air area and prompted evacuations -- one in a series of blazes that have scorched more than 83,000 acres, burned scores of buildings and forced tens of thousands of people to flee their homes over three days.

The closure of I-405 -- a significant north-south artery in the country's second-largest city -- came after flames swept down the foothills toward the highway near Sepulveda Pass and the Getty Center arts complex as stunned motorists drove by shortly before 6 a.m.

"It was dark until I saw a gigantic ball of orange," motorist Tiffany Lynette Anderson wrote on Instagram, where she posted a picture of fire raging beside the highway before it shut down. "On absolute fire. I'm grateful to be safe -- truly grateful."

The Moraga Estate, a large home and vineyard owned by Fox media mogul Rupert Murdoch, is also reportedly in the path of the flames, according to Bloomberg.

Heavy Santa Ana winds blamed for spreading the infernos still threaten to multiply the destruction.

The winds might die down during sunlight Wednesday, but they're expected to pick up in the evening and Thursday -- perhaps as gusty as 50 mph, posing a risk of further spread.

Smoke collected even in areas that weren't burning. Health officials warned people in the heavily populated San Fernando Valley and other parts of the northern Los Angeles area to limit their time outdoors.

Latest developments

• The largest fire: The biggest blaze is the Thomas Fire in Ventura County, burning at least 65,000 acres, including parts of Ventura, a city of more than 100,000 people along the Pacific coast. It started Monday evening in a rural area and spread to the city. Officials said the fire has destroyed at least 150 buildings, including an evacuated mental health facility.

• Curfew enacted: On Tuesday, the city of Ventura declared a daily curfew, beginning from 10 p.m. to 5 a.m., to protect residents and prevent crime such as looting in evacuation areas.

• Told to leave: More than a quarter of Ventura's residents (38,000 people) have been told to evacuate. More than 12,000 buildings were under threat, officials said Wednesday.

• Creek Fire in northern Los Angeles: The second-largest inferno is the Creek Fire, having burned around 11,000 acres in and near northern Los Angeles and the San Fernando Valley.

• Mass exodus: About 150,000 people in Los Angeles were under evacuation orders Tuesday. The number Wednesday, after the orders given because of the fire near I-405, wasn't immediately clear.

• Power outage: About 43,000 homes were without power Tuesday night, according to Southern California Edison. More outages are possible because flames were burning along power transmission paths, a spokeswoman said.

• Other fires: The Rye Fire near Santa Claritain Los Angeles County grew to about 7,000 acres. That fire was spotted near the Six Flags Magic Mountain in Valencia.

In San Bernardino County, two smaller fires sprang up. One is fully contained, while the Little Mountain Fire is at 100 acres.

Fire could go on for days

The Thomas Fire spanned 65,000 acres (about 101 square miles) in Ventura County, which sits just north and west of Los Angeles.

The number of destroyed structures was unknown due to the intensity of the fire, but officials had estimated about 150 buildings early Tuesday.

In Los Angeles, the Creek Fire went from 4,000 acres to 11,000 in a matter of hours Tuesday.

"We expect to be out here all week fighting and containing this fire," Los Angeles Mayor Eric Garcetti said.

The fires spewed so much smoke that they were captured in a NASA image from space.

California Gov. Jerry Brown declared an emergency for Ventura County, freeing state resources such as the National Guard to support response efforts.

'Everything that I have ... is gone'

Fires tore through neighborhoods, razing homes to the ground, reducing them to gray smoldering ashes. It also burned Vista del Mar Hospital, an 82-bed mental health facility in northwestern Ventura, which was fully evacuated two hours before, county fire engineer Richard Macklin said.

Residents who had to evacuate from their homes described tense moments as the fires rapidly approached.

"The embers from the trees were dropping on our cars," said Mary Robinson, a Ventura resident, who fled Monday night. "We're so blessed that we still have a house. I can't believe it, because the fire was so close."

Another Ventura resident, Samantha Wells-Zuniga, escaped with her family and watched her apartment complex burn down.

Speaking through tears, she told CNN affiliate KABC, "We've been watching all these disasters on TV, you really don't think about when it happens to you, and what do you pack in that moment?"

They escaped with a few Christmas presents.

"Now, everything that I have, except for my lovely family, is gone," she said.

The Thomas Fire jumped to thousands of acres with startling speed as Santa Ana winds, blowing as fast as 35 to 50 mph, carried its embers. The fire quickly devoured dry chaparral, as the county has been in a period of moderate drought.